Icy temperatures of -18.7 degrees were measured in the northeastern state of Brandenburg on Friday night, the German weather service (DWD) reported on Saturday.
The mercury dropped even further elsewhere, with the village of Bertsdorf-Hörnitz, Saxony, claiming the record with an overnight temperature of -21.3C.
But the weather will get considerably milder as the weekend progresses, the DWD reported, with temperatures leaping up as high as +6C in the state of Hesse on Sunday. "People with a weak circulation will have real problems," warned a DWD spokeswoman.
The sudden rise will be caused by a high pressure region bringing milder wins in from the Atlantic.
The DWD warned that the resulting rain could cause ice on the roads in the meantime. Surface ice caused flight cancellations at Frankfurt Airport last Sunday and also played havoc with public transport systems around the country. The weather is also likely to remain overcast and rainy in the coming days.
But the sudden warmth is not the forerunner of an early spring, the DWD added. February could well turn cold again, a spokeswoman said.